The reaction of Li2S and P2S5 with Li4[SnS4], a recently discovered, good Li(+) ion conductor, yields Li10SnP2S12, the thiostannate analogue of the record holder Li10GeP2S12 and the second compound of this class of superionic conductors with very high values of 7 mS/cm for the grain conductivity and 4 mS/cm for the total conductivity at 27 °C. The replacement of Ge by Sn should reduce the raw material cost by a factor of ~3.

The catalytic dehydrocoupling/dehydrogenation of N-methylamine-borane, MeNH(2)·BH(3) (7), to yield the soluble, high molecular weight poly(N-methylaminoborane) (8a), [MeNH-BH(2)](n) (M(W) > 20 000), has been achieved at 20 °C using Brookhart's Ir(III) pincer complex IrH(2)POCOP (5) (POCOP = [μ(3)-1,3-(OPtBu(2))(2)C(6)H(3)]) as a catalyst. The analogous reaction with ammonia-borane, NH(3)·BH(3) (4), gave an insoluble product, [NH(2)-BH(2)](n) (8d), but copolymerization with MeNH(2)·BH(3) gave soluble random copolymers, [MeNH-BH(2)](n)-r-[NH(2)-BH(2)](m) (8b and 8c). The structures of polyaminoborane 8a and copolymers 8b and 8c were further analyzed by ultrahigh resolution electrospray mass spectrometry (ESI-MS), and 8a, together with insoluble homopolymer 8d, was also characterized by (11)B and (1)H solid-state NMR, IR, and wide-angle X-ray scattering (WAXS). The data indicate that 8a-8c are essentially linear, high molecular weight materials and that the insoluble polyaminoborane 8d possesses a similar structure but is of lower molecular weight (ca. 20 repeat units), presumably due to premature precipitation during its formation. The yield and molecular weight of polymer 8a was found to be relatively robust toward the influence of different temperatures, solvents, and adduct concentrations, while higher catalyst loadings led to higher molecular weight materials. It was therefore unexpected that the polymerization of 7 using 5 was found to be a chain-growth rather than a step-growth process, where high molecular weights were already attained at about 40% conversion of 7. The results obtained are consistent with a two stage polymerization mechanism where, first, the Ir catalyst 5 dehydrogenates 7 to afford the monomer MeNH═BH(2) and, second, the same catalyst effects the subsequent polymerization of this species. A wide range of other catalysts based on Ru, Rh, and Pd were also found to be effective for the transformation of 7 to polyaminoborane 8a. For example, polyaminoborane 8a was even isolated from the initial stage of the dehydrocoupling/dehydrogenation of 7 with [Rh(μ-Cl)(1,5-cod)](2) (2) as the catalyst at 20 °C, a reaction reported to give the N,N,N-trimethyl borazine, [MeN-BH](3), under different conditions (dimethoxyethane, 45 °C). The ability to use a variety of catalysts to prepare polyaminoboranes suggests that the synthetic strategy should be applicable to a broad range of amine-borane precursors and is a promising development for this new class of inorganic polymers.

The new nitridoalumosilicate phosphor SrAlSi 4 N 7 :Eu 2+ has been synthesized under nitrogen atmosphere at temperatures up to 1630 °C in a radio-frequency furnace starting from Sr metal, R-Si 3 N 4 , AlN, and additional Eu metal. The crystal structure of the host compound SrAlSi 4 N 7 has been solved and refined on the basis of single-crystal and powder X-ray diffraction data. In the solid, there is a network structure of corner-sharing SiN 4 tetrahedra incorporating infinite chains of all edge-sharing AlN 4 tetrahedra running along [001] (SrAlSi 4 N 7 : Pna2 1 (No. 33), Z ) 8, a ) 11.742(2) Å, b ) 21.391(4) Å, c ) 4.966(1) Å, V ) 12.472(4) Å 3 , 2739 reflections, 236 refined parameters, R1 ) 0.0366). The Eu 2+ -doped compound SrAlSi 4 N 7 :Eu 2+ shows typical broadband emission originating from dipole-allowed 4f 6 ( 7 F J )5d 1 f 4f 7 ( 8 S 7/2 ) transitions in the orange-red spectral region (λ max ) 632 nm for 2% Eu doping level, 450 nm excitation) with a spectral width of FWHM ) 2955 (( 75) cm -1 and a Stokes shift ∆S ) 4823 (( 100) cm -1 . The luminescence properties make the phosphor an attractive candidate material as red component in trichromatic warm white light LEDs with excellent color rendition properties.